A net-type decorative light string or a curtain-type one is popular in prior known use. This known structure uses a single elastic hook to connect with the electrical wire of which the connecting strength is not enough. In use, even an accidental pulling, the bulb holder will be separated from the wires. The net-type or curtain-type decorative configuration is then incomplete.
Accordingly, it is a main purpose of the present invention to provide a connecting structure of a bulb holder, which is capable of firmly connecting with the electric wires, that solves the problem of the prior design.